Electronic digital thermostats typically have one or more programmable modes of fan operation. These modes may include an automatic mode based on temperature-related demands or requirements of the heating/cooling system, a time mode based on the time of day and a continuous mode for continuous operation. These thermostats commonly include user interfaces or programming pads for selecting among the available modes of operation.
A variety of thermostats, including ones with multiple modes of operation, are known in the art for controlling heating/cooling systems and air circulation systems. However, none of the previously available thermostats gave the user the option to turn the fan on, upon demand, for a preselected period.
The ability to turn the fan on and make it operate continuously for a preselected period, regardless of temperature or time, would give the user improved control over the environment. The user could ensure that the fan adequately ventilates the room, independent of temperature and time, and the user need not remain to turn the fan off.
What has been needed is a thermostat with an easily selected mode to operate the fan upon demand for a preselected period (and preferably one of a plurality of preselected periods).